The present invention relates to a fuel-feeding device for feeding liquid fuel contained in a fuel tank of an automobile to an automobile engine (an internal-combustion engine).
A fuel-feeding device is taught by, for example, Japanese Laid-Open Patent Publication No. 2005-69171. This fuel-feeding device includes a reservoir cup disposed in a fuel tank, a fuel pump capable of feeding (pumping) liquid fuel contained in the fuel tank to an engine via a feeding port, a pressure regulator capable of controlling a pressure of the liquid fuel fed to the engine (i.e., a fuel pressure), and a jet pump. The jet pump is arranged and constructed to inject the pressurized liquid fuel pumped from a relief port of the fuel pump into the reservoir cup, thereby introducing (drawing) the liquid fuel outside of the reservoir cup into the reservoir cup with the injected liquid fuel.
However, according to the known fuel-feeding device, it is not possible to control a flow rate of the liquid fuel pumped from the relief port of the fuel pump. Therefore, when the liquid fuel is pumped from the feeding port of the fuel pump to the engine in a reduced flow rate, a flow rate of the liquid fuel from the relief port of the fuel pump toward the jet pump can be relatively higher than the flow rate of the liquid fuel from the feeding port of the fuel pump toward the engine. That is, when a reduced volume of liquid fuel is pumped from the fuel pump, a substantial portion of the pumped liquid fuel is fed to the jet pump and not to the engine. Therefore, even if the reduced volume of liquid fuel should be fed to the engine, the fuel pump must be actuated to pump a relatively large volume of liquid fuel. That is, the fuel pump must be actuated at a relatively high speed (large load) in order to feed the reduced volume of liquid fuel to the engine. This means that when the reduced volume of liquid fuel should be fed to the engine, the fuel pump must be wastefully actuated.
Thus, there is a need in the art for an improved fuel-feeding device for feeding liquid fuel of an engine.